Many electronic devices include a user interface device for allowing user interaction and user input. One user interface device is a button or a key. Conventional buttons include mechanical components to actuate a switch to indicate a button press or button activation. Mechanical buttons also provide a tactile feedback to the user to indicate the button has been pressed. More recently, touch-sensor buttons are being used in some applications to replace mechanical buttons. One type of touch-sensor button operates by way of capacitance sensing, utilizing capacitance sensor elements. The capacitance detected by a capacitance sensor changes as a function of the proximity of a conductive object on the sensor element. The conductive object can be, for example, a stylus or a user's finger. In a touch-sensor button, a change in capacitance detected by each sensor due to the proximity of a conductive object can be measured by a variety of methods. Regardless of the method, usually an electrical signal representative of the capacitance detected by each capacitance sensor is processed by a processing device, which in turn produces electrical or optical signals representative of the button or sensor activation of the touch-sensor button.